Large capacity rechargeable batteries are currently being investigated for use in electric vehicles. The ultimate feasibility of electric vehicles depends on significantly reducing the associated costs. Reduction in the costs of battery assemblies is particularly important.
Lithium ion batteries are an important type of battery technology. Most battery assemblies, including lithium ion battery assemblies, include a plurality of individual electrochemical cells. Typically, such electrochemical cells include an anode and a cathode. Typically, the anode includes a metal sheet or foil (usually copper metal) over-coated with a graphitic layer. Similarly, the cathode usually includes a metal sheet or foil (usually aluminum metal) over-coated with a lithium-containing layer. Finally, electrochemical cells include an electrolyte which is interposed between the anode and the cathode. Terminals allow the generated electricity to be used in an external circuit. Electrochemical cells produce electricity via an electrochemical reaction.
For high power application, a plurality of battery cells are utilized and assembled into a battery module. Moreover, such battery modules are assembled into battery packs which include a cooling system and related electronics for operating the batteries. The cooling systems typically include a plurality of metallic cooling fins (e.g., copper and/or aluminum) interspersed between the battery cells. It turns out that the assembly of such battery modules is fairly difficult with respect to aligning the cooling fins and the battery cells.
Accordingly, there is a need for improved battery module assemblies and for methods of constructing such battery module assemblies.